US1077380A - Quick-break switching mechanism. - Google Patents

Description

H. G. WELLMAN,

QUICK BREAK swmcame MECHANISM.

APPLICATION FILED FEB.5,1012, 77 380 Patented Nov. 4, 1913.

3 SHEETS-SHEET 1.

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1,077,380, Patented Nov. 4, 1913.

3 HEETSSHEBT Z.

I 20 72 KG )1 State of Ohio, have invented a HOLLEY G. WELLMAN, F CLEVELAND, oHIo.

QUICK-BREAK SWITCHING MECHANISM.

To all 'wlwmz't may concern:

Be it known that I, HoLLEY G. WELLMAN, a citizen of the'Unit-ed States, residing at Cleveland, in the county of Guyahogaand certain new and useful Improvement in Quick-Break Switching Mechanism, of which the follow-- i ing is a full, clear, and exact description.

i illustrated This invention relates to improvements in quick break electric controllers or switch mechanisms, and particularly to that type in a patent to; Thomas W. Thomas, for quick breaking electric switch mechanism, No. 1,021,016,1Vlarch 26th, 1912.

I In the above mentioned application, there is disclosed a controller including a number of pivotally mounted switch levers .or arms which are adapted to be closed in a predetermined order by cams on a manually operable cam shaft when the latter is turned in one direction, and to be opened with a snap action by springs acting on the switch arms, whenthe cam shaft is turned in the reverse direction, and when certain raised or operative portions of the cams are moved out of engagement with the switch arms.

The present invention is, in one aspect an improvement over this though certain features are capable of it has for its main object to broader and more general application, and provide means whereby arcing at the contacts is decreased and is fact practically eliminated.

In accordance with the present invention, to ellmmate arcing at the contacts of a switching mechanism or controller having one or more switch levers which are adapted to be actuated by mechanical closing devices, such as cams on a cam shaft and to be opened by springs or equivalent means, I

.prov de means preferably in the form of magnets which acting .on the levers hold the contacts in engagement until the switch and quickly,

closing deviceshave moved out of engagement with the levers, and then release the latter so that they may be moved by the springs quickly tofull open osition. thus temporarily holding t e levers in closed "positionor with the contacts in en gagement until after the switch closing d'e. vices have moved out of engagement with the levers, the latter may be opened freely ment of'the controllerorswitch handle.

My invention may be further briefly sum-' marized as consisting in certa n novel de Specification of Letters Patent. Application filed February 5, 1912.

controller, al

and D in this case being ported on the shaft E regardless of therate of movethree being Serial No. 675,505.

tails of construction and combinations and arrangements of parts which will be dc scribed in the specification and the appended claims.

Referri-n-g'now to the figures of the draw-.

ing, .Wherein I have shown my.invention applied to a motor controller,'Figure 1 is a plan view-of the controller';'Fig. 2 is an end view of the same looking toward the end at the bottom of Fig. 1; Fig. 3 is a transverse sectional view along the line 33 of Fig. 1; Fig. 4 is a detail sectional view of a portion of the magnet controlling switch on line 4 4: of Fig. 1; Fig. 5 I view showing conventionally the controller and motor, the connections between the same and the connections for the magnets.

Referring nowto the drawings, 10 represents an insulating base on which is supported by a number of brackets-l1, a manually operable cam shaft A, consisting preferably of a number of alined sections A, A A which are secured together but are insulated from one another by insulating disks B and B, thesection A extending beyond the insulating baseand having provision for connection with an operating or controller handle, not shown. This cam shaft A is provided with a number of cams C, C, C C C C (1 ,0 C 0", C and C, said cams being preferablycast integral with the respective the cam shaft and each being provided with an are shaped raised or operating-portion 0' adapted to engage the switch levers or suitable rollers provided thereon and with recessed portions 0 The raised portions of the difi'erent cams are of different arcuate lengths and the connecting portions between the raised and recessed portions are preferably slightly curved, as shown at 0 Arranged below or in the planes of the cams C to C are a number of switch levers or arnls D,-D2 D37 D57 D67 D7, a DD D100 and D, which are pivotally mounted on two alined shafts E", E which are also supported by the brackets 11, the levels D pivota'lly supsubstantially Patented Nov. 4, 1913.

sections A and A of and the other levers set forth in is a dlagrammatic- D toD being 'pivotally supported on the shaft E It maybe here stated that the levers, D to D are utilized for connecting the-armature and the fields of the motor to the. line or current supplying conductors,

adapted to be closed simultaneare connected sprin gs ously when the controller handle is moved forwardly to the first operative position, and three being adapted to be closed. when the controller handle is moved to the first operative position in the reverse direction to reverse the motor, and the switch arms D to D are employed for cutting resistance sections in or out of the motor field circuitfor either forward or reverse movement of the controller handle and successively or in sequence in a well known manner.

All the switch levers are provided at their rear ends with extensions 12 to which '13 which tend to open said levers, and forwardly of the supporting shafts E and E the levers are provided with rollers 14, having trunnion-like supports which engage within suitable bearing openings in the side walls of the levers, the levers being somewhat channel -or U- shaped in cross section. These rollers are so located that they will be engaged by the cams C to or switch levers and hold thesame closed as long as the arc-shaped raised portions 0 are in engagement with said rollers. The levers D to D are preferably provided at their forward ends with laminated contact brushes 15, the forward ends of which are beveled and are adapted to engage inclined portions 16 of stationary contact members 16 which are secured to the base 10, and are provided also with spring contact fingers 17 which are provided at their free ends with auxiliary contacts 18 adapted to engage stationary auxiliary contacts 19 which are supported on the bracket 16, as shown clearly in Figs. 2 and 3. The auxiliary contacts 18 are adapted to engage the contacts 19 prior to the engagement of the laminated contact brushes 15 with the stationary contacts 16, and said auxiliary contacts 18 are.

adapted to leave or be separated from the contacts 19 after the contacts 15 are separated from the contacts 16, as in the customary manner. The switch levers D to D are provided at their forward ends simply with contact fingers 20 provided with contacts 21 which are adapted to engage stationary contacts 22 also mounted on the base 10. g

It will be apparent that by turning the shaft successively through the forward positions or successively through thereverse positions, the switches will be closed by the engagement of the raised or operating portions 0 of the cams with the rollers 14:, the

levers being actuated by the cams so as to cause the engagement of the movable contacts with the stationary contacts, and being held in' their downward or closed positions as long as the raised'portions of the cams are in engagement with the rollers. It will be apparent also that when the raised will be operated G which close the switches of said strip 33 extending over- 0 of the cams are moved out of engagement with the rollers 14:, may be opened by the springs, the rollers moving into the recessed portions 0 of the cams. It will be notedalso that if the opening movement of all'the levers is dependent wholly upon the disengagement of the raised portions of the cams and the rollers 14, a very appreciable amount of time will be required for the opening movement, even though the inclined portions 0 of the cams are made as abrupt as possible. Therefore even though the cam shaft were moved from first operative position (forward or reverse), to off position as quickly as it could be moved by hand, there would nevertheless be considerable arcin at the contacts of those switches which d1sconnect' the motor armature and field from the line circuit.

In order to avoid arcing at the contacts when the controller is moved to off position so as to disconnect the motor armature and field from the line circuit, I provide means whereby the opening of the switch levers at which arcing would occur is rendered independent of the actual disengagement of the cams and the corresponding rollers 1 1. This is accomplished in this caseby pro viding in cooperative relation with the switch levers D to D at which the arcing would ordinarily take place a plurality of magnets 23, one of which is arranged below or in line with each of these switch levers so as to hold the levers in closed position or partially closed position until the cams which actuate the said levers have reached positions such that the portions 0 are quite out of engagement with the corresponding rollers 14: so that when the magnets are deenergized, the levers may be opened freely by the springs 13. These magnets cooperate with armatures 24, which are loosely attached to the levers and are connected to the latter by stems 25 which pass through openings in the levers, as shown most clearly in Fig. 3, coil springs 26 serving to normally hold the arinatures 24: away from the switch arms.

The magnets are energized and deenergized or connected and disconnected from the line conductors .to be referred to resently by means of a switch D which is a apted to be opened 'and closed by the cam O on the end of the camshaft section A. This switch D includes a bar or strip 28 which is adapted to be rocked or tipped in one direction or the other by the cam G and is pivotally connected midway between its ends to a pin or plunger 29 which is slidably mounted in a bracket 30 and is yieldingly pressed outward by a spring 31. The member 28 is rovided at each end with a cross bar 32 of insulating material, to which is connected a contact strip 33 with the ends the top of 1 'theinsulating cross member 32. Each end of the' movable switch member of switch D is adapted-tocooperate with three-separate stationary the magnets and the switch D, it maybe well being had'to Fig. ranged on the cam shaft'that when the latter or the controller-handle. is moved to the by- -conductor 45 conductor '46, all the sections of wardly from off to; the ,tion, the switch arms to point out the order in which "the switch levers areopened and closed, and the man'- ner in which the connections are made'between the controller and motor, reference 5. The cams are so arfirst-operative position in the forward direction, switch levers D, D and D are closed. This connects the motor field and armature to line or main current supplying conductorswhich are designated 40 and'41,with

all the sections of 'the'resistance-R im the field circuit. The connections andthe circuit are as follows -assuming that the conductor .40 is a positive conductor. Current passes from this conductor-by a conductor 42 to the shaft section E; thence through switch arm D I and condu'ctor:43 to one terminal of the motor armature 44; thence and other suitable connections toswitch arm D section E to the switch arm D;

the resistance R, and by conductor 47 to one side of the motor field 46;'and thence by conductor 47 a to the-other main current su'pplyingcon ductor 41.. As-the controller arm is moved forwardly through the other operative posito D are operated. successively so as to cut out different resisttions,the switch arms D ance sections. I When the controller handle is moved back' first operative posi- D D .remain open, and the switches 'D ,"D and D are' simul taneou'sly closed. This reverses the direction' of'currentthrough the motor armature with all the resistance sections in the field circuit so that the motor-will beoperated in the reverse direction at its lowestspeed. When the controller handle is moved'backward to the first operative position, the circuit through the controller and motor is as followsz from the main supply conductor 40 to the shaft section .E thence by switch lever D and conductor 45 to one terminal of the motor armature; thence 'from the opposite terminal of the motor-armature by conductor 43 and aconnection 43 toswitch 'leve'r D and to shaft section E and from shaft section. E

to switch lever B; thence designated 34, 35, and 36,,

stationary theme by the shaft thence by by conductor 46, sections of resistance Rand conductor 47 to one terminal of the field and thence from theopposite ter-' minal of the field winding by conductor 47 winding to the main current supplying conductor 41. \Vhen the controller handle is moved back- .wardly, through the other operative posi' to D are closed tions, the switch levers D successively and the different resistance secti'o'ns are successively cut out of the field circuit.

NVhen the controller handle or cam shaft is in offposition, thecam C which controls the switch D is in a; position substantially at right angles to the member 28 of the switch D or engages at substantially the 'middle portion-of this member 28 so as 'to hold the same out of engagement" with the contacts at each end thereof. When, however, the controller handle is moved from off position toward the first operative position, wa'rdly, the member 28 of switch D is rocked by the cam O so that the contact members atone end or the other: thereof engage with the corresponding set of stationary contacts so as to energize the magnets 23 by connecting the'same to the main supply conductors 40 and 41. -When the switch member 28 is rocked in either direction, the circuit through the magnets may be traced as follows: from the maincond-u'ctor 40by conductor 42 to shaft section E, and from the shaft section E by connection 50 to themember 28 of the switch D thence to one or the other stationary contacts 35 or 38 of switch D; thence by connections '52.to and through the coils of all the magnets 23; thence by connections 53 to either of the end contacts 34 or 37 thence by one of the cross contact members 33 of the switch D to one of the end stationary contacts 36 or 39 and by conductor 54 to the main conductor 41. These magnets will remain energized while the controller handle is moved forwardly or rearwardly through its different operative positions and during a portion of its movement from either first forward or first backward position to off position. In other words the magnets remain energized until afterthe cams C, C and C, which had previously actuated and retained in closed position the switch levers D, D and D or until after the cams C C and G which had previously actuated and retained in closed position the switch levers D D and D move out of engagement or out of operative relation with the corresponding rollers on the switch levers. Just before the controller handle reaches off position, the magnets are decnergized by the action of the cam C on the magnet controlling switch D, and. the switch levers which (were held in closed positionare then quickly opened by of the middle cover all modifications which invention.

the corresponding springs 13. When the cams move out of engagement with the rollers, the switch levers have a slight opening movement until they engage suitable stop members on the outer ends of the pins 25, which support the magnet armatures 24, this movement being sufficient to separate the laminated contact brushes 15 from the stationary cont-acts. The magnets, however, by the pull on the armatures 52A, prevent further outward movement of the switch levers until after the cams have moved out of operative relation with respect to the rollers, and until after the magnets are deenergized when the auxiliary contacts are separated very quickly in the manner above stated. By thus providing means for retaining the switch. levers closed or in positions such that the auxiliary contacts are in engagement, independently of the cams, and until the cams are free of the rollers, and by then releasing the switch levers so that they may be opened with a snap action by the springs, sparking is minimized and the main object of my invention, as stated at the beginning of the specification, is tained.

While I have shown my invention applied to a motor controller of one particular type, it can be very effectively employed in other forms of controllers, and other types of switching apparatus employing any number of switch arms, and I aim in my claims to do not involve a departure from the spirit and scope of my Having thus I claim is:

1. In a quick break electric switch, the combination of a movable switch member, a movable switch closing deviceadapted to engage the said member to cause the closure of the switch, and to permit the opening of the switch when moved out of engagement with said switch member, and means comprising a magnet for holding the switch closed independently of said closing device until after the latter is moved a predetermined distance away from said switch member.

2. In a quick break electric switch, the combination of a movable switch member, a switch closing device adapted to engage said member to close the switch and to permit the opening of the switch when moved out of engagement with said member, means comprising a magnet for holding the switch closed independently of said device, and means for deenergizing said magnet when said device is moved a predetermined distance out of engagement with said member.

3. In a quick break electric switch,'the combination of a mgvable switch member, means for moving said switch member in described my invention, what one direction to open the switch, a switch,

closing device adapted to cause the closure of the switch whenthe device is moved in one direction, and to permit the opening of the switch when said device is moved in the reverse direction, and means independent of said device for temporarily preventing the opening of the switch until after said device is moved a predetermined distance in said reverse direction.

4:. In a quick break electric switch, the combination of a pivoted switch lever, means for moving said lever in one direction to open the switch, a switch closing device adapted to engage said lever and to close the switch when said device is moved in one direction and to permit the opening of the switch when said device is moved in the reverse direction, and means separate from said device for preventing the opening of the switch until said device is moved out of engagement with the lever, a predetermined distance in said reverse direction.

5. In a quick break electric switch, the combination of a movable switch member, means for moving the same in one direction to open the switch, a switch closing device adapted to close the switch when said device is moved in one direction and to permit the opening of the switch when moved in the reverse direction, means comprising a magnet for holding the switch closed, and means for deenergizing said magnet when said device has moved a predetermined distance in said reverse direct1on.

6. In a quick break electric switch, the combination of a movable switch member, means for moving the same in one direction to open the switch, a movable switch closing device adapted when moved in one direction to close the switch, and when moved in the reverse direction to permit the switch to be opened, a magnet for holding the switch closed, and means comprising a switch for causing the deenergization of the magnet when said device is moved a predetermined distance in said vreverse direction.

7. In a quick break electric switch, a pivoted switch lever, a spring for moving the same in one direction to open the switch, a rotatable operating shaft, a device on said shaft for moving the said lever to close the switch, a magnet for retaining the lever in closed position after the said device is out of operative relation with said lever, and a switch actuated by said shaft for causing the energization and deenergization of the magnet.

8. In a quick break electric switch, the combination of a switch lever, a spring for moving the same in one direction, a rotatable operating shaft, a cam on said shaft for actuating said lever to close the switch, a magand is moved 7 ing the net for preventin by said cam unti operative relation the opening of the switch after the latter is out of with said lever, and a switch actuated by said operating shaft for controlling said magnet.

9. In a quick break electric switch, the combination of a switchlever, a spring for movsame in one direction to open the switch, a rotatable operating shaft, a cam on said shaft for actuating said lever to close the switch, a magnet for holding said switch lever in closed position independently of said cam, a switch for controlling said magnet, and a cam on said shaft for actuating said last named switch.

10. Ina controller, the combination of a plurality of pivoted switch arms, springs for moving said arms in one direction to open position, a rotatable operating shaft, cams or moving said arms in the opposite direction to closed position, means comprising a plurality of magnets for preventing the opening of the arms, until after the cams are free of said arms, and a switch controlled by said shaft for causing the energization or denergization of the magnets.

11. In a quick break electric switch, the combination of a switch lever, a roller on said lever, a spring for moving the lever in one direction to open the switch, a rotatable operatin shaft, a cam on said shaft provided with a recessed portion and with a raised portion adapted to engage said roller so as to close the switch and to holdthe same in closed position, means for preventing the opening of the switch by said spring until after the recessed portion of the cam is opposite said roller, and means for causing the release of'said switch lever, whereby the same may be opened with a snap action by said spring.

'12. In a quick break electric switch, the

combination of main and auxiliary stationary contact members, a switch lever having main and auxiliary contact members adapted to engage respectively the main and auxiliary stationary contact members, a spring for moving the switch lever in one direction to open the switch, a rotatable operating shaft, a cam on said shaft for actuating the said lever to close the switch, and a magnet acting on said lever for preventing the separation of the auxiliary contacts by said spring until after the cam is out of operative relation with said lever.

13. In a switching apparatus, a movable switch member, a switch operating device adapted to move said switch member in one direction, to close the switch when said operating device is moved from off position in either direction, and means separate from said device for temporarily holding the switch closed until said device is moved a predetermined distance toward ofli' position.

In testimony whereof, I hereunto aflix my signature in the presence of two witnesses.

HOLLEY G. WELLMAN.

Witnesses:

H. R. SULLIVAN, A. F, KwIs.

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